FDT-25W Wall Mounter Ultrasonic Flowmeter
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2.7.6 N-method Installation
Rarely used method.
2.8 Installation Checkup
Through the checkup of the installation, one can: check the receiving signal strength, the signal quality
Q value, the traveling time difference of the signals, the estimated liquid speed, the measured traveling
time of the signals and the calculated traveling time ratio. Therefore, optimum measurement result and
longer running time of the instrument can be achieved.
2.8.1 Signal Strength
Signal strength indicates the amplitude of receiving ultrasonic signals by a 3-digit number. [00.0] means
there is no signal detected and [99.9] refers to the maximum signal strength that can be received.
Although the instrument works well if the signal strength ranges from 50.0 to 99.9, stronger signal
strength should be pursued, because a stronger signal means a better result. The following methods
are recommended to obtain stronger signals:
(1) Relocate a more favorable location, if the current location is not good enough for a stable and
reliable flow reading, or if the signal strength is lower than 60.0.
(2) Try to polish the outer surface of the pipe, and apply more coupler to increase the signal strength.
(3) Adjust the transducers both vertically and horizontally while checking the varying signal strength,
stop at the highest position, and then check the transducers spacing to make sure the transducers
spacing is the same as what the M25 shows.